We found this circuit for musical instruments in the March 1992 Radio Electronics magazine. The circuit has outputs according to the desired scale from a crystal oscillator at the indicated frequency.
This circuit adds a beep to turn on with car flashers that do not have this feature. A 47 ohm to...
Depending on the value of C1, this oscillator can produce signals of up to 1 MHz. For a capacitor of 10...
This commercial circuit, sold under the designation H531 in Japan in the 1960s, used three...